Envelope tracking amplifier apparatus incorporating single-wire peer-to-peer bus

ABSTRACT

An envelope tracking (ET) amplifier apparatus is provided. The ET amplifier apparatus includes an ET integrated circuit (ETIC) and a distributed ETIC (DETIC) coupled to a single-wire bus that correspond to a first bus access priority and a second bus access priority, respectively. The ETIC and the DETIC can contend for access to the single-wire bus by asserting a bus contention indication(s) when the single-wire bus is in a defined bus state configured to permit bus contention. In a non-limiting example, a winner for the single-wire bus is a peer device having a highest bus access priority between the ETIC and the DETIC. In this regard, each of the ETIC and the DETIC can have a chance to initiate communications over the single-wire bus, thus making it possible for the single-wire bus to function based on bidirectional peer-to-peer (P2P) bus architecture capable of supporting more application and/or deployment scenarios.

RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patentapplication Ser. No. 62/847,609, filed on May 14, 2019, the disclosureof which is incorporated herein by reference in its entirety.

This application is related to U.S. patent application Ser. No.16/675,335, entitled “SINGLE-WIRE PEER-TO-PEER BUS,” filed on Nov. 6,2019, now U.S. Pat. No. 11,113,220, the disclosure of which is herebyincorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

The technology of the disclosure relates generally to an envelopetracking (ET) amplifier apparatus.

BACKGROUND

Mobile communication devices have become increasingly common in currentsociety. The prevalence of these mobile communication devices is drivenin part by the many functions that are now enabled on such devices.Increased processing capabilities in such devices means that mobilecommunication devices have evolved from being pure communication toolsinto sophisticated mobile multimedia centers that enable enhanced userexperiences.

The redefined user experience requires higher data rates offered bywireless communication technologies, such as Wi-Fi, long-term evolution(LTE), and fifth-generation new-radio (5G-NR). To achieve the higherdata rates in mobile communication devices, a mobile communicationdevice may employ a power amplifier(s) to amplify a radio frequency (RF)signal(s) to a higher output power prior to radiating the RF signal viaan antenna(s).

However, the increased output power of RF signal(s) can lead toincreased power consumption and thermal dissipation, thus compromisingoverall performance and user experiences. Envelope tracking (ET) is apower management technology designed to improve efficiency levels of PAsto help reduce power consumption and thermal dissipation in the mobilecommunication device. As such, it may be desirable to enable ET in themobile communication device whenever possible. Notably, the RF signal(s)communicated in different wireless communication systems may correspondto different modulation bandwidths (e.g., from 80 KHz to over 200 MHz).As such, it may be further desirable to ensure that the poweramplifier(s) can maintain optimal efficiency across a wide range ofmodulation bandwidth.

In many mobile communication devices, the power amplifier(s) and theantenna(s) are typically located in an RF front-end (RFFE) circuitcommunicatively coupled to a transceiver circuit(s) via an RFFE bus asdefined in the MIPI® alliance specification for radio frequencyfront-end control interface, version 2.1. However, not allcommunications require a two-wire serial bus like the RFFE bus. In somecases, a single-wire serial bus may be sufficient or even desired forcarrying out certain type of communications between circuits. As such,it may be possible to provide a single-wire bus, either concurrent to orindependent of, the RFFE bus in the mobile communication device.

SUMMARY

Aspects disclosed in the detailed description include an envelopetracking (ET) amplifier apparatus. The ET amplifier apparatus includesan ET integrated circuit (ETIC) and a distributed ETIC (DETIC) coupledto a single-wire bus. The ETIC corresponds to a first bus accesspriority and the DETIC corresponds to a second bus access priority. Inexamples discussed herein, any of the ETIC and the DETIC can contend foraccess to the single-wire bus by asserting a bus contentionindication(s) (either concurrently or independently) when thesingle-wire bus is in a defined bus state configured to permit buscontention. In a non-limiting example, a winner for the single-wire busis a peer device having a highest bus access priority between the ETICand the DETIC. In this regard, each of the ETIC and the DETIC can have achance to initiate communications over the single-wire bus, thus makingit possible for the single-wire bus to function based on bidirectionalpeer-to-peer (P2P) bus architecture capable of supporting moreapplication and/or deployment scenarios.

In one aspect, an ET amplifier apparatus is provided. The ET amplifierapparatus includes an ETIC coupled to a single-wire bus andcorresponding to a first bus access priority. The ET amplifier apparatusalso includes a DETIC coupled to the single-wire bus and correspondingto a second bus access priority lower than the first bus accesspriority. At least one of the ETIC and the DETIC is configured to asserta bus contention indication when the single-wire bus is in a defined busstate configured to permit bus contention. The at least one of the ETICand the DETIC is also configured to determine whether the bus contentionindication is successful based on the first bus access priority and thesecond bus access priority. The at least one of the ETIC and the DETICis also configured to communicate over the single-wire bus in responseto the bus contention indication being successful.

Those skilled in the art will appreciate the scope of the disclosure andrealize additional aspects thereof after reading the following detaileddescription in association with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thisspecification illustrate several aspects of the disclosure and, togetherwith the description, serve to explain the principles of the disclosure.

FIG. 1A is a schematic diagram of an exemplary single-wire bus (SuBUS)architecture in which a master circuit is configured to communicate witha slave circuit(s) over a SuBUS having a single wire;

FIG. 1B is a schematic diagram providing an exemplary illustration ofone or more SuBUS telegrams communicated over the SuBUS of FIG. 1A;

FIG. 2 is a schematic diagram of an exemplary single-wire peer-to-peer(P2P) bus apparatus including a number of peer devices each configuredto contend for an opportunity to initiate communication over asingle-wire bus;

FIG. 3A is a time sequence diagram providing an exemplary illustrationof one embodiment of a single-wire P2P bus contention and arbitrationmechanism that enables the peer devices to contend for access to thesingle-wire bus of FIG. 2 based on respective bus access priorities;

FIG. 3B is a time sequence diagram providing an exemplary illustrationof another embodiment of a single-wire P2P bus contention andarbitration mechanism that enables the peer devices to contend foraccess to the single-wire bus of FIG. 2 based on respective bus accesspriorities;

FIG. 4 is a schematic diagram of an exemplary peer device, which can beprovided in the single-wire P2P bus apparatus of FIG. 2 as any of thepeer devices; and

FIG. 5 is a schematic diagram of an exemplary envelope tracking (ET)amplifier apparatus configured to incorporate the single-wire P2P busapparatus of FIG. 2 to support P2P communications between chips and/orcircuits.

DETAILED DESCRIPTION

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the embodiments andillustrate the best mode of practicing the embodiments. Upon reading thefollowing description in light of the accompanying drawing figures,those skilled in the art will understand the concepts of the disclosureand will recognize applications of these concepts not particularlyaddressed herein. It should be understood that these concepts andapplications fall within the scope of the disclosure and theaccompanying claims.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present disclosure. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element such as a layer, region, orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present.Likewise, it will be understood that when an element such as a layer,region, or substrate is referred to as being “over” or extending “over”another element, it can be directly over or extend directly over theother element or intervening elements may also be present. In contrast,when an element is referred to as being “directly over” or extending“directly over” another element, there are no intervening elementspresent. It will also be understood that when an element is referred toas being “connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present.

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” may be used herein to describe a relationshipof one element, layer, or region to another element, layer, or region asillustrated in the Figures. It will be understood that these terms andthose discussed above are intended to encompass different orientationsof the device in addition to the orientation depicted in the Figures.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a,” “an,” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes,” and/or “including” when used herein specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms used herein should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthis specification and the relevant art and will not be interpreted inan idealized or overly formal sense unless expressly so defined herein.

Aspects disclosed in the detailed description include an envelopetracking (ET) amplifier apparatus. The ET amplifier apparatus includesan ET integrated circuit (ETIC) and a distributed ETIC (DETIC) coupledto a single-wire bus. The ETIC corresponds to a first bus accesspriority and the DETIC corresponds to a second bus access priority. Inexamples discussed herein, any of the ETIC and the DETIC can contend foraccess to the single-wire bus by asserting a bus contentionindication(s) (either concurrently or independently) when thesingle-wire bus is in a defined bus state configured to permit buscontention. In a non-limiting example, a winner for the single-wire busis a peer device having a highest bus access priority between the ETICand the DETIC. In this regard, each of the ETIC and the DETIC can have achance to initiate communications over the single-wire bus, thus makingit possible for the single-wire bus to function based on a bidirectionalpeer-to-peer (P2P) bus architecture capable of supporting moreapplication and/or deployment scenarios.

Before discussing a single-wire P2P bus apparatus of the presentdisclosure, a brief overview of a conventional single-wire bus (SuBUS)structure is first provided with reference to FIGS. 1A-1B to helpunderstand basic operational principles between a conventional SuBUSmaster and a conventional SuBUS slave(s). The discussion of specificexemplary aspects of the single-wire P2P bus apparatus of the presentdisclosure starts below with reference to FIG. 2.

In this regard, FIG. 1A is a schematic diagram of an exemplaryconventional SuBUS architecture 10 in which a master circuit 12 isconfigured to communicate with one or more slave circuits 14(1)-14(M)over a SuBUS 16 consisting of a single wire 18. The master circuit 12 isconfigured to always initiate a SuBUS telegram communication over theSuBUS 16 by communicating a SuBUS telegram(s). As such, the conventionalSuBUS architecture 10 is also known as a “master-slave busarchitecture.” The slave circuits 14(1)-14(M) may provide a datapayload(s) to the master circuit 12 over the SuBUS 16 in response toreceiving the SuBUS telegram(s) from the master circuit 12. Hereinafter,when the master circuit 12 and the slave circuits 14(1)-14(M) arecommunicating the SuBUS telegram(s) and/or the data payload(s) over theSuBUS 16, the master circuit 12 and the slave circuits 14(1)-14(M) aresaid to be in a bus communication mode.

FIG. 1B is a schematic diagram providing an exemplary illustration ofone or more SuBUS telegrams 20, 22 communicated over the SuBUS 16 ofFIG. 1A. Each of the SuBUS telegrams 20, 22 includes a start of sequence(SOS) sequence 24 and a SuBUS command sequence 26. The SuBUS commandsequence 26 may correspond to a predefined SuBUS operation (e.g.,register-read or register-write). The SOS sequence 24 always precedesthe SuBUS command sequence 26 and is always communicated from the mastercircuit 12 to the slave circuits 14(1)-14(M) in FIG. 1A.

The SuBUS telegram 22, which succeeds the SuBUS telegram 20, may beseparated from the SuBUS telegram 20 by a fast-charge period 28 thatstarts at time T₁ and ends at time T₂ (T₂>T₁) and an idle period 30 thatstarts at time T₂ and ends at time T₃ (T₃>T₂). The fast-charge period 28is configured to allow each of the slave circuits 14(1)-14(M) to draw ahigher charging current via the SuBUS 16 and carry out a defined slaveoperation. In this regard, the SuBUS 16 is said to be in a fast-chargestate during the fast-charge period 28. The idle period 30 may be ano-activity period in which the master circuit 12 and the slave circuits14(1)-14(M) may be inactive to help conserve power. Accordingly, theSuBUS 16 is said to be in an idle state during the idle period 30.During the fast-charge period 28 and the idle period 30, the SuBUS 16 ismaintained at a bus voltage V_(BUS) that is greater than zero volts(V_(BUS)>0 V).

The master circuit 12 is configured to suspend the SuBUS telegramcommunication over the SuBUS 16 during the fast-charge period 28 and theidle period 30. Accordingly, the master circuit 12 and the slavecircuits 14(1)-14(M) are configured to refrain from communicating SuBUStelegram(s) and data payload(s) from time T₁ to T₃. In this regard, theSuBUS 16 can be said to be in a suspension mode between time T₁ and T₃.

In the conventional SuBUS architecture 10, the SuBUS telegramcommunication over the SuBUS 16 can only be initiated by the mastercircuit 12. As such, none of the slave circuits 14(1)-14(M) may initiatethe SuBUS telegram communication with the master circuit 12. Forexample, if any of the slave circuits 14(1)-14(M) has an urgent need tocommunicate the data payload(s) to the master circuit 12 at time T₁, theslave circuit would be forced to wait till at least time T₃ to have achance to access the SuBUS 16, thus hindering the ability of the slavecircuit 14(1)-14(M) to fulfill a time-constrained communication need(s).As such, it may be desirable to adapt the conventional SuBUSarchitecture 10 to allow any of the slave circuits 14(1)-14(M) toinitiate a SuBUS telegram and/or a data payload communication(s) withthe master circuit 12 over the SuBUS 16.

In this regard, FIG. 2 is a schematic diagram of an exemplarysingle-wire P2P bus apparatus 32 including a number of peer devices34(1)-34(N) each configured to contend for an opportunity to initiatecommunication over a single-wire bus 36. In a non-limiting example, thesingle-wire bus 36, which consists of a single wire, is identical to theSuBUS 16 in FIG. 1A. In examples discussed herein, the peer devices34(1)-34(M) are assigned a number of bus access priorities P₁-P_(N),respectively, with P₁ being the highest bus access priority and P_(N)being the lowest bus access priority (P₁>P₂>P₃> . . . >P_(N)). In thisregard, the peer device 34(1) is assigned the highest bus accesspriority P₁ and referred to as “a first peer device” hereinafter. Thepeer devices 34(2)-34(N) are associated with descending bus accesspriorities P₂-P_(N), respectively. Hereinafter, the peer devices34(2)-34(N) are collectively referred to as “at least one second peerdevice” and the bus access priorities P₂-P_(N) are collectively referredto as “at least one second bus access priority.”

As discussed in detail below, one or more selected peer devices amongthe peer devices 34(1)-34(N) may assert a bus contention indication(s)when the single-wire bus 36 is in a defined bus state (e.g., thefast-charge state and/or the idle state) configured to permit buscontention. However, only one of the selected peer devices (alsoreferred to as “bus winning peer device”) with a highest bus accesspriority can gain access to the single-wire bus 36 to initiate telegramcommunication over the single-wire bus 36. For example, if peer devices34(1), 34(3), and 34(N), which are associated respectively with the busaccess priorities P₁, P₃, and P_(N), all assert the bus contentionindication when the single-wire bus 36 is in the defined bus state, onlythe peer device 34(1) can gain the access to the single-wire bus 36 as aresult of the highest bus access priority P₁. Accordingly, thebus-winning peer device 34(1) can initiate the telegram communicationwith the peer devices 34(3) and 34(N) over the single-wire bus 36.

By allowing the peer devices 34(1)-34(N) to contend for access to thesingle-wire bus 36 based on respectively assigned bus access prioritiesP₁-P_(N), it may be possible for any of the peer devices 34(1)-34(N) toinitiate the telegram communication over the single-wire bus 36. As aresult, it may be possible for the single-wire bus 36 to function basedon a P2P bus architecture, as opposed to the conventional master-slavebus architecture 10 of FIG. 1A, to support more application and/ordeployment scenarios.

To help understand a single-wire P2P bus contention and arbitrationmechanism employed by the single-wire P2P bus apparatus 32 that allowsthe peer devices 34(1)-34(N) to contend for access to the single-wirebus 36 based on the assigned bus access priorities P₁-P_(N), FIGS. 3Aand 3B are discussed below as non-limiting examples. Common elementsbetween FIGS. 2, 3A, and 3B are shown therein with common elementnumbers and will not be re-described herein.

In this regard, FIG. 3A is a time sequence diagram providing anexemplary illustration of one embodiment of the single-wire P2P buscontention and arbitration mechanism that enables the peer devices34(1)-34(N) to contend for access to the single-wire bus 36 of FIG. 2based on respective bus access priorities P₁-P_(N). Notably, the peerdevices 34(1)-34(N) are only allowed to contend for access to thesingle-wire bus 36 when the single-wire bus 36 is in the defined busstate, such as the idle state. As such, each of the peer devices34(1)-34(N) may be required to monitor the single-wire bus 36 (e.g., bymonitoring the idle period 30 in FIG. 1B) to determine whether thesingle-wire bus 36 is in the defined bus state. As mentioned earlier inFIG. 1B, the single-wire bus 36 is maintained at the bus voltage V_(BUS)(V_(BUS)>0 V). As such, the peer devices 34(1)-34(N) may be configuredto monitor the bus voltage V_(BUS) to determine whether the single-wirebus 36 is in the defined bus state.

As illustrated in FIG. 3A, the single-wire bus 36 is in either the fastcharge state or the idle state prior to time T₀. If the single-wire bus36 is in the fast-charge state, the peer device 34(1) (the first peerdevice) can be configured to provide a charging current to the peerdevices 34(2)-34(N) (collectively the at least one second peer device).For more detail on how the first peer device 34(1) provides the chargingcurrent to any of the peer devices 34(2)-34(N) during the fast-chargestate, please refer to FIG. 3 of U.S. patent application Ser. No.16/549,116, entitled “SINGLE-WIRE BUS APPARATUS” and filed on Aug. 23,2019. Notably, when the single-wire bus 36 is in the fast charge state,all of the peer devices 34(1)-34(N) are configured to refrain fromcommunicating telegrams and data payloads over the single-wire bus 36.If the single-wire bus 36 is in the idle state, the single-wire bus 36is maintained at the bus voltage V_(BUS). Accordingly, the peer devices34(1)-34(N) may communicate among each other over the single-wire bus36. In this regard, the idle state can correspond to the defined busstate configured to permit bus contention by any of the peer devices34(1)-34(N).

At time T₀, at least one selected peer device among the peer devices34(1)-34(N) asserts a bus contention indication to indicate an intent toaccess the single-wire bus 36. Accordingly, the single-wire bus 36 issaid to be in a wakeup period 38. In a non-limiting example, theselected peer device can assert the bus contention indication by pullingthe bus voltage V_(BUS) of the single-wire bus 36 to a predefinedthreshold V_(REF) (0 V≤V_(REF)<V_(BUS)) and subsequently restore thesingle-wire bus 36 to the bus voltage V_(BUS).

Given that all of the peer devices 34(1)-34(N) may be monitoring the busvoltage V_(BUS) of the single-wire bus 36, the peer devices 34(1)-34(N)would all be able to learn that a peer device(s) has asserted the buscontention indication in response to the single-wire bus 36 being pulledfrom the bus voltage V_(BUS) down to the predefined threshold V_(REF).As such, it may not be necessary for another peer device among the peerdevices 34(1)-34(N) to assert its own bus contention indication.However, it should be appreciated that all of the peer devices34(1)-34(N) may still assert respective bus contention indicationsconcurrent to or independent from the selected peer device.

The single-wire bus 36 may not return to the bus voltage V_(BUS) if anyof the peer devices 34(1)-34(N) is asserting the bus contentionindication. As such, the single-wire bus 36 may be held at thepredefined threshold V_(REF) for a period Δt before returning to the busvoltage V_(BUS). Notably, the single-wire bus 36 may not be able toclimb back to the bus voltage V_(BUS) immediately due to inherentramp-up delay. For example, the single-wire bus 36 may not return to thebus voltage V_(BUS) until time T₁.

The first peer device 34(1), which has the highest bus access priorityP₁, may be configured to immediately end the wakeup period 38 bybroadcasting an opening SOS sequence 40 over the single-wire bus 36 attime T₁. In this regard, the opening SOS sequence 40 is broadcasted overthe single-wire bus 36 between time T₁ and T₃. Alternatively, the firstpeer device 34(1) may also be configured to end the wakeup period 38after a hysteresis period HP (e.g., one symbol) from time T₁ bybroadcasting the opening SOS sequence 40 over the single-wire bus 36 attime T₂ (HP=T₂−T₁). In this regard, the opening SOS sequence 40 isbroadcasted over the single-wire bus 36 between time T₂ and T₃. Theopening SOS sequence 40 may be configured to start telegramcommunication over the single-wire bus 36 and provide a timing referencefor the second peer devices 34(2)-34(N) on the single-wire bus 36.

Starting at time T₃, the peer devices 34(1)-34(N) are configured tobroadcast a number of bus request telegrams 42(1)-42(N), respectively,in a sequential order determined by the bus access priorities P₁-P_(N).In this regard, the first peer device 34(1) first starts broadcastingthe bus request telegram 42(1) (also referred to as “first bus requesttelegram”) at time T₃. Subsequently, the second peer devices 34(2)-34(N)broadcast the bus request telegrams 42(2)-42(N) (collectively referredto as “at least one second bus request telegram”) sequentially based onthe bus access priorities P₂-P_(N).

Each of the bus request telegrams 42(1)-42(N) includes a data field 44configured to indicate a respective intention to access the single-wirebus 36, regardless of whether the respective peer device 34(1)-34(N) hasasserted the bus contention intention during the wakeup period 38. Forexample, one of the peer devices 34(1)-34(N) may have asserted the buscontention intention during the wakeup period 38. The peer device 34(3)detected the asserted bus contention intention by monitoring the busvoltage V_(BUS). As a result, the peer device 34(3) may have decided toforego the opportunity to assert its own bus contention indication, eventhough the peer device 34(3) also has an intention to access thesingle-wire bus 36. Nevertheless, the peer device 34(3) may still signalthe intention to access the single-wire bus 36 in the data field 44 ofthe bus request telegram 42(3).

In addition to the data field 44, each of the bus request telegrams42(1)-42(N) may also include a respective parity field 46 succeeding thedata field 44. Each of the bus request telegrams 42(1)-42(N) may furtherinclude a respective bus park (BP) field 48 succeeding the parity field46. In a non-limiting example, the bus request telegrams 42(1)-42(N) areconfigured to have an identical duration (e.g., three symbols).

Each of the peer devices 34(1)-34(N) may be configured to monitor and/ordecode all of the bus request telegrams 42(1)-42(N) to help determinewhether any peer device 34(1)-34(N) with a higher bus access priorityhas requested access the single-wire bus 36. Accordingly, any peerdevice 34(1)-34(N) with a lower bus access priority is required torefrain from initiating telegram communication over the single-wire bus36. For example, if the first peer device 34(1) has indicated in thedata field 44 of the bus request telegram 42(1) an intention to accessthe single-wire bus 36, the first peer device 34(1) will become thebus-winning peer device due to the highest bus access priority P₁. As aresult, all of the second peer devices 34(2)-34(N) are required torefrain from initiating telegram communication over the single-wire bus36. As such, it may be possible to avoid potential bus collision basedon such self-disciplinary arbitration mechanism.

At time T_(X), the peer devices 34(1)-34(N) have completed broadcastingthe bus request telegrams 42(1)-42(N), respectively. In a non-limitingexample, each of the peer devices 34(1)-34(N) can determine time T_(X)based on the equation (Eq. 1) below.T _(X) =T ₃ +N*D _(RQST)  (Eq. 1)

In the equation above, N represents a count of the peer devices34(1)-34(N) and D_(RQST) represents a duration of each of the busrequest telegrams 42(1)-42(N). Accordingly, the bus winning peer devicecan start communicating one or more protocol telegrams 50 at time T_(X).

After the bus winning peer device completes communicating the protocoltelegrams 50, the single-wire bus 36 returns to the fast-charge stateand the idle state. In this regard, any of the peer devices 34(1)-34(N)may start asserting the bus contention indication again as describedabove.

FIG. 3B is a time sequence diagram providing an exemplary illustrationof another embodiment of the single-wire P2P bus contention andarbitration mechanism that enables the peer devices 34(1)-34(N) tocontend for access to the single-wire bus 36 of FIG. 2 based onrespective bus access priorities P₁-P_(N).

In this embodiment, only the first peer device 34(1) is configured todetermine time T_(X) based on the equation (Eq. 1). At time T_(X), thefirst peer device 34(1) is configured to broadcast a closing SOSsequence 52, which can be identical to or different from the opening SOSsequence 40. The first peer device 34(1) may be further configured tobroadcast a BP sequence 54 subsequent to broadcasting the closing SOSsequence 52. The BP sequence 54 is configured to provide an explicitindication of time T_(Y) at which the bus winning peer device can startcommunicating the protocol telegrams 50.

FIG. 4 is a schematic diagram of an exemplary peer device 56, which canbe provided in the single-wire P2P bus apparatus 32 of FIG. 2 as any ofthe peer devices 34(1)-34(N). Common elements between FIGS. 2 and 4 areshown therein with common element numbers and will not be re-describedherein.

In a non-limiting example, the peer device 56 includes a push/pull (PP)driver 58, an open-drain (OD) driver 60, a voltage comparator 62, avoltage detector 64, and a data receiver 66 (e.g., an input Schmitt).The peer device 56 may also include a controller 68, which can beimplemented by a microprocessor, a microcontroller, or afield-programmable gate array (FPGA), as an example.

When the single-wire bus 36 is in the idle state, a resistor 70 causesthe bus voltage V_(BUS) of the single-wire bus 36 to be substantiallyclose to a supply voltage V_(IO) (e.g., V_(IO)−V_(BUS)≤70 mV). Thevoltage comparator 62 compares the bus voltage V_(BUS) against thepredefined threshold V_(REF) and provides a comparison result 72 to thevoltage detector 64. Based on the comparison result 72, the voltagedetector 64 determines that the bus voltage V_(BUS) is higher than thepredefined threshold V_(REF) and provides an indication 74 to thecontroller 68. Accordingly, the controller 68 places the PP driver 58 ina tri-stated mode by asserting a PP control signal 76 (e.g., as alogical HIGH). To assert a bus contention intention when the single-wirebus 36 is in the idle state, the controller 68 can activate the ODdriver 60 by asserting a bus contention control signal 78 (e.g., as alogical HIGH) to pull the bus voltage V_(BUS) down to the predefinedthreshold V_(REF), while keeping the PP driver 58 in the tri-statedmode.

Again, the voltage comparator 62 compares the bus voltage V_(BUS)against the predefined threshold V_(REF) and provides the comparisonresult 72 to the voltage detector 64. Based on the comparison result 72,the voltage detector 64 determines that the bus voltage V_(BUS) is lowerthan or equal to the predefined threshold V_(REF) and provides theindication 74 to the controller 68. Accordingly, the controller 68 maydeactivate the OD driver 60 by de-asserting the bus contention controlsignal 78 (e.g., as a logical LOW). As a result, the resistor 70 maycause the single-wire bus 36 to return to the bus voltage V_(BUS).

The peer device 56 may determine whether the bus contention indicationis successful based on the single-wire P2P bus contention andarbitration mechanism as discussed in FIGS. 3A and 3B. If the peerdevice 56 determines that the bus contention indication is successful,the controller 68 may de-assert the PP control signal 76 (e.g., as alogical LOW) to put the PP driver 58 out of the tri-stated mode.Accordingly, the peer device 56 may communicate a command telegram(s) 80via the PP driver 58 and/or receive a data payload(s) 82 via the datareceiver 66. In a non-limiting example, the controller 68 is configuredto de-assert the bus contention control signal 78 prior to de-assertingthe PP control signal 76.

In contrast, if the peer device 56 determines that the bus contentionindication is unsuccessful, the controller 68 may maintain the PPcontrol signal 76 (e.g., at logical HIGH) to block the commandtelegram(s) 80 from the single-wire bus 36. The peer device 56 mayattempt to re-assert the bus contention indication when the single-wirebus 36 returns to the defined bus state.

The single-wire P2P bus apparatus 32 of FIG. 2 can be provided in anenvelope tracking (ET) amplifier apparatus to enable P2P communicationsbetween chips and/or circuits. In this regard, FIG. 5 is a schematicdiagram of an exemplary ET amplifier apparatus 84 configured toincorporate the single-wire P2P bus apparatus 32 of FIG. 2. Commonelements between FIGS. 2 and 5 are shown therein with common elementnumbers and will not be re-described herein.

The ET amplifier apparatus 84 includes an ET integrated circuit (ETIC)86 and a distributed ETIC (DETIC) 88. In a non-limiting example, theETIC 86 and the DETIC 88 are provided in different dies, such assystem-on-chips (SOCs), physically separated from each other. The ETIC86 includes an ET voltage circuit 90, a tracker circuit 92, and an ETICcontroller 94, which can be a microprocessor, a microcontroller, or aFPGA, as an example.

The ETIC 86 includes a primary output port 96 coupled to a primaryamplifier circuit 98 (denoted as “PPA”) configured to amplify a primaryradio frequency (RF) signal 100 based on an ET modulated voltage V_(CC).In a non-limiting example, the primary RF signal 100 is a cellularcommunication signal, such as a long-term evolution (LTE) or afifth-generation new-radio (5G-NR) communication signal.

The ET voltage circuit 90 is configured to generate and provide the ETmodulated voltage V_(CC) to the primary output port 96. Notably, theprimary RF signal 100 may be modulated in a wide range of modulationbandwidths and correspond to a variety of peak-to-average ratios (PARs).As such, the ET voltage circuit 90 may also need to source/sink ahigh-frequency current I_(AC) (e.g., an alternating current) to/from theprimary output port 96.

The tracker circuit 92 is configured to generate a low-frequency currentI_(DC) (e.g., a direct current). The ETIC 86 may include a switchingcircuit 102 coupled to the tracker circuit 92, the primary output port96, and an auxiliary output port 104. The switching circuit 102 mayinclude a first switch S₁ and a second switch S₂, which can becontrolled by the ETIC controller 94 to selectively provide thelow-frequency current I_(DC) to the primary output port 96 or theauxiliary output port 104.

The DETIC 88 includes a distributed ET (DET) voltage circuit 106, a lowdropout (LDO) regulator 108 (denoted as “LDO”), and a DETIC controller110, which can be a microprocessor, a microcontroller, or a FPGA, as anexample. The DETIC 88 is coupled to an auxiliary amplifier circuit 112(denoted as “APA”) configured to amplify an auxiliary RF signal 114based on a DET modulated voltage V_(DCC). In a non-limiting example, theauxiliary RF signal 114 is a Wi-Fi communication signal.

The DET voltage circuit 106 is configured to generate and provide theDET modulated voltage V_(DCC) to the auxiliary amplifier circuit 112 foramplifying the auxiliary RF signal 114. The auxiliary amplifier circuit112 may be selectively coupled to the auxiliary output port 104 toreceive the low-frequency current I_(DC) from the tracker circuit 92 orto the LDO regulator 108 to receive a distributed low-frequency currentI_(DDC).

The ETIC 86 is coupled to the DETIC 88 via the single-wire bus 36. Inexamples discussed herein, the ETIC 86 and the DETIC 88 are associatedwith bus access priorities P₁ and P₂ (P₁>P₂), respectively. In thisregard, the ETIC 86 may correspond to the first peer device 34(1) andthe DETIC 88 may correspond to one of the second peer devices34(2)-34(N), as previously described in FIG. 2.

In one non-limiting example, the DETIC 88 can assert a bus contentionindication when the single-wire bus 36 is in the defined bus state. Ifthe bus contention indication is successful, the DETIC 88 maycommunicate the protocol telegrams 50 to the ETIC 86 to request to drawthe low-frequency current I_(DC) from the tracker circuit 92. Uponreceiving the protocol telegrams 50 from the DETIC 88, the ETICcontroller 94 may determine whether the primary amplifier circuit 98 isactive to amplify the primary RF signal 100. If the primary amplifiercircuit 98 is active, the ETIC controller 94 may decline the requestfrom the DETIC 88. Otherwise, the ETIC controller 94 may close thesecond switch S₂ and open the first switch S₁ such that the auxiliaryamplifier circuit 112 can draw the low-frequency I_(DC) from the trackercircuit 92. Accordingly, the DETIC controller 110 may deactivate the LDOregulator 108 in the DETIC 88.

When the DETIC controller 110 determines that the auxiliary amplifiercircuit 112 has completed amplifying the auxiliary RF signal 114, theDETIC controller 110 may assert the bus contention indication when thesingle-wire bus 36 is once again in the defined bus state. If the buscontention indication is successful, the DETIC controller 110 maycommunicate the protocol telegrams 50 to cause the ETIC controller 94 todecouple the auxiliary output port 104 from the auxiliary amplifiercircuit 112.

In case the ETIC controller 94 declines the request by the DETIC 88 todraw the low-frequency current I_(DC) from the tracker circuit 92, theDETIC controller 110 may activate the LDO regulator 108 to provide thedistributed low-frequency current I_(DDC) to the auxiliary amplifiercircuit 112. The DETIC controller 110 may attempt to assert the buscontention indication again when the single-wire bus 36 is once again inthe defined bus state.

In another non-limiting example, the ETIC controller 94 determines thatthe primary amplifier circuit 98 becomes active to amplify the primaryRF signal 100 and thus in need of the low-frequency current I_(DC),while the auxiliary amplifier circuit 112 is still drawing thelow-frequency current I_(DC) from the tracker circuit 92. In thisregard, the ETIC controller 94 needs to wait until the single-wire bus36 is in the defined bus state to assert a bus contention indication.Given that the ETIC 86 is associated with the higher bus access priorityP₁, the ETIC controller 94 would become the bus winning peer deviceafter asserting the bus contention indication. Accordingly, the ETICcontroller 94 may communicate the protocol telegrams 50 to the DETIC 88to inform the DETIC controller 110 that the ETIC 86 is in need of thetracker circuit 92. Accordingly, the DETIC controller 110 may activatethe LDO regulator 108 to provide the distributed low-frequency currentI_(DDC) to the auxiliary amplifier circuit 112. Subsequently, the DETICcontroller 110 may inform the ETIC controller 94 to decouple the trackercircuit 92 from the auxiliary amplifier circuit 112. Accordingly, theETIC controller 94 opens the second switch S₂ and closes the firstswitch S₁ to provide the low-frequency current I_(DC) to the primaryamplifier circuit 98.

Those skilled in the art will recognize improvements and modificationsto the embodiments of the present disclosure. All such improvements andmodifications are considered within the scope of the concepts disclosedherein and the claims that follow.

What is claimed is:
 1. An envelope tracking (ET) amplifier apparatuscomprising: an ET integrated circuit (ETIC) coupled to a single-wire busand corresponding to a first bus access priority; and a distributed ETIC(DETIC) coupled to the single-wire bus and corresponding to a second busaccess priority lower than the first bus access priority; wherein atleast one of the ETIC and the DETIC is configured to: assert a buscontention indication when the single-wire bus is in a defined bus stateconfigured to permit bus contention; determine whether the buscontention indication is successful based on the first bus accesspriority and the second bus access priority; and communicate over thesingle-wire bus in response to the bus contention indication beingsuccessful.
 2. The ET amplifier apparatus of claim 1 further comprisingthe single-wire bus.
 3. The ET amplifier apparatus of claim 1 whereinthe defined bus state corresponds to an idle state configured to enablecommunication between the ETIC and the DETIC.
 4. The ET amplifierapparatus of claim 1 wherein the ETIC and the DETIC are provided indifferent dies.
 5. The ET amplifier apparatus of claim 1 configured tomaintain the single-wire bus at a bus voltage during the defined busstate.
 6. The ET amplifier apparatus of claim 5 wherein the at least oneof the ETIC and the DETIC is further configured to assert the buscontention indication by pulling down the bus voltage of the single-wirebus to a predefined threshold and subsequently restoring the single-wirebus to the bus voltage.
 7. The ET amplifier apparatus of claim 1wherein: the ETIC comprises: a primary output port; an auxiliary outputport; an ET voltage circuit configured to generate an ET modulatedvoltage at the primary output port; a tracker circuit configured togenerate a low-frequency current; a switching circuit coupled to thetracker circuit, the primary output port, and the auxiliary output port;and an ETIC controller configured to selectively couple the trackercircuit to the primary output port or the auxiliary output port; and theDETIC comprises: a distributed ET voltage circuit configured to generatea distributed ET modulated voltage; a low-dropout (LDO) regulatorconfigured to generate a distributed low-frequency current; and a DETICcontroller.
 8. The ET amplifier apparatus of claim 7 further comprisinga primary amplifier circuit coupled to the primary output port andconfigured to amplify a primary radio frequency (RF) signal based on theET modulated voltage.
 9. The ET amplifier apparatus of claim 8 whereinthe primary RF signal is a cellular communication signal selected fromthe group consisting of: a long-term evolution (LTE) communicationsignal and a fifth-generation new-radio (5G-NR) communication signal.10. The ET amplifier apparatus of claim 8 further comprising anauxiliary amplifier circuit coupled to the DETIC and the auxiliaryoutput port and configured to amplify an auxiliary RF signal based onthe distributed ET modulated voltage.
 11. The ET amplifier apparatus ofclaim 10 wherein the auxiliary RF signal is a Wi-Fi communicationsignal.
 12. The ET amplifier apparatus of claim 10 wherein the DETIC isconfigured to: determine that the auxiliary amplifier circuit is activeto amplify the auxiliary RF signal; assert a respective bus contentionindication when the single-wire bus is in the defined bus state; andcommunicate one or more protocol telegrams to the ETIC over thesingle-wire bus to request to draw the low-frequency current from thetracker circuit in response to the respective bus contention indicationbeing successful.
 13. The ET amplifier apparatus of claim 12 wherein theDETIC controller is configured to activate the LDO regulator to providethe distributed low-frequency current to the auxiliary amplifier circuitin response to the respective bus contention indication beingunsuccessful.
 14. The ET amplifier apparatus of claim 13 wherein theDETIC is further configured to re-assert the respective bus contentionindication when the single-wire bus is in the defined bus state again inresponse to the respective bus contention indication being unsuccessful.15. The ET amplifier apparatus of claim 12 wherein: the ETIC controlleris further configured to: determine that the primary amplifier circuitis inactive; control the switching circuit to couple the tracker circuitto the auxiliary output port to provide the low-frequency current to theauxiliary amplifier circuit; and notify the DETIC controller via thesingle-wire bus that the request to draw the low-frequency current isgranted; and the DETIC controller is configured to deactivate the LDOregulator.
 16. The ET amplifier apparatus of claim 12 wherein: the ETICcontroller is further configured to: determine that the primaryamplifier circuit is active; control the switching circuit to couple thetracker circuit to the primary output port to provide the low-frequencycurrent to the primary amplifier circuit; and notify the DETICcontroller via the single-wire bus that the request to draw thelow-frequency current is declined; and the DETIC controller isconfigured to activate the LDO regulator to provide the distributedlow-frequency current to the auxiliary amplifier circuit.
 17. The ETamplifier apparatus of claim 16 wherein the DETIC is further configuredto re-assert the respective bus contention indication when thesingle-wire bus is in the defined bus state again in response to theETIC declining the request to draw the low-frequency current from theETIC.
 18. The ET amplifier apparatus of claim 10 wherein the ETIC isconfigured to: determine that the primary amplifier circuit becomesactive to amplify the primary RF signal while the auxiliary amplifiercircuit is drawing the low-frequency current from the tracker circuit;assert a respective bus contention indication when the single-wire busis in the defined bus state; and communicate one or more protocoltelegrams to the DETIC over the single-wire bus to stop the auxiliaryamplifier circuit from drawing the low-frequency current from thetracker circuit in response to the respective bus contention indicationbeing successful.
 19. The ET amplifier apparatus of claim 18 wherein theETIC is further configured to re-assert the respective bus contentionindication when the single-wire bus is in the defined bus state again inresponse to the respective bus contention indication being unsuccessful.20. The ET amplifier apparatus of claim 18 wherein: the ETIC controlleris further configured to control the switching circuit to couple thetracker circuit to the primary output port to provide the low-frequencycurrent to the primary amplifier circuit; and the DETIC controller isconfigured to activate the LDO regulator to provide the distributedlow-frequency current to the auxiliary amplifier circuit.